Répondre :
A = (y+8)²
=y²+16y+64
B = (3y-9)²
=9y²-54y+81
C = (y+7)(y-7)
= y²-7y+7y-49
= y²-49
D = (4y-5)(4y+5)
= 16y²+20y-20y-25
= 16y²-25
E = (2y-5)²-(4y+1)²
= (4y²-20y+25)-(16y²+8y+1)
= 4y²-20y+25-16y²-8y-1
= -12y²-28y+24
=y²+16y+64
B = (3y-9)²
=9y²-54y+81
C = (y+7)(y-7)
= y²-7y+7y-49
= y²-49
D = (4y-5)(4y+5)
= 16y²+20y-20y-25
= 16y²-25
E = (2y-5)²-(4y+1)²
= (4y²-20y+25)-(16y²+8y+1)
= 4y²-20y+25-16y²-8y-1
= -12y²-28y+24